Free Audio Restoration Tools

I developed a free tool for the restoration of wow and flutter artifacts, especially for bootleg recordings. It can work with any source medium and has several modes of operation. You can remove both irregular and cyclic distortions. In most cases, you can get much better results than with Capstan. Of course, it's not fully automatic, but you have the choice of several different tracing algorithms to make work easier.

Here's a screenshot of the program:

And a comparison of the effect of cyclic wow removal and the raw source:

Re: Free Wow & Flutter Removal - pyrespeeder

Not exactly flutter related, but a nice offshoot that grew from the same code:

I recently created another tool that is very much needed and I haven't ever found a commercial solution for.

Automatic Dropout Healing

The idea is to fix very short dropouts that still have audio, but just more quiet than the surrounding regions. It gives a lot more stability to poor tape sources. Here's a before and after of the script (CSNY - Another 4Way Street), which runs unsupervised on complete files at once:

It operates independently on stereo channels, and adapts to the individual nature of each dropout by correcting it in several bands.
The only problem for now is that dropouts must be of a relatively constant length throughout, but in my tests so far, this has not caused any trouble.